ART: Clean up arm64 kNumberOfXRegisters usage.
Avoid undefined behavior for arm64 stemming from 1u << 32 in
loops with upper bound kNumberOfXRegisters.
Create iterators for enumerating bits in an integer either
from high to low or from low to high and use them for
<arch>Context::FillCalleeSaves() on all architectures.
Refactor runtime/utils.{h,cc} by moving all bit-fiddling
functions to runtime/base/bit_utils.{h,cc} (together with
the new bit iterators) and all time-related functions to
runtime/base/time_utils.{h,cc}. Improve test coverage and
fix some corner cases for the bit-fiddling functions.
Bug: 13925192
Change-Id: I704884dab15b41ecf7a1c47d397ab1c3fc7ee0f7
diff --git a/runtime/base/bounded_fifo.h b/runtime/base/bounded_fifo.h
index d04840a..7bcd382 100644
--- a/runtime/base/bounded_fifo.h
+++ b/runtime/base/bounded_fifo.h
@@ -17,16 +17,19 @@
#ifndef ART_RUNTIME_BASE_BOUNDED_FIFO_H_
#define ART_RUNTIME_BASE_BOUNDED_FIFO_H_
+#include "base/bit_utils.h"
+#include "base/logging.h"
+
namespace art {
// A bounded fifo is a fifo which has a bounded size. The power of two version uses a bit mask to
// avoid needing to deal with wrapping integers around or using a modulo operation.
-template <typename T, const size_t MaxSize>
+template <typename T, const size_t kMaxSize>
class BoundedFifoPowerOfTwo {
+ static_assert(IsPowerOfTwo(kMaxSize), "kMaxSize must be a power of 2.");
+
public:
BoundedFifoPowerOfTwo() {
- // TODO: Do this with a compile time check.
- CHECK(IsPowerOfTwo(MaxSize));
clear();
}
@@ -45,7 +48,7 @@
void push_back(const T& value) {
++size_;
- DCHECK_LE(size_, MaxSize);
+ DCHECK_LE(size_, kMaxSize);
// Relies on integer overflow behavior.
data_[back_index_++ & mask_] = value;
}
@@ -61,9 +64,9 @@
}
private:
- static const size_t mask_ = MaxSize - 1;
+ static const size_t mask_ = kMaxSize - 1;
size_t back_index_, size_;
- T data_[MaxSize];
+ T data_[kMaxSize];
};
} // namespace art